LEO Pharma Acquires Worldwide Rights to Dersimelagon for EPP, XLP
Key Takeaways
- LEO Pharma agreed to acquire worldwide rights to dersimelagon from Tanabe Pharma for up to $435 million in upfront and near-term milestone payments, plus potential downstream milestones and tiered royalties.
- Dersimelagon is an investigational once-daily oral melanocortin 1 receptor (MC1R) agonist developed for erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP).
- An NDA for dersimelagon was submitted to the FDA in June 2026 following Phase 3 development; the therapy remains investigational and has not been approved by the FDA or another regulatory authority.
LEO Pharma has entered into an agreement to acquire worldwide rights to dersimelagon from Tanabe Pharma, adding a late-stage investigational therapy for erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) to its rare dermatology pipeline.
Under the agreement, LEO Pharma will pay up to $435 million in upfront and near-term milestone payments, with additional potential downstream milestones and tiered royalties on net sales. The transaction remains subject to customary closing conditions and applicable regulatory approvals.
Oral MC1R Agonist Reaches FDA Review
Dersimelagon is an investigational, once-daily oral melanocortin 1 receptor (MC1R) agonist designed to increase melanin production and reduce sunlight penetration and phototoxic reactions. EPP and XLP are rare genetic disorders characterized by painful reactions following exposure to sunlight. Other manifestations may include erythema, swelling, rash, and burning sensations; liver complications can occur in some patients.
Tanabe Pharma submitted a New Drug Application to the US Food and Drug Administration (FDA) in June 2026 for dersimelagon for EPP and XLP. The drug has received FDA Fast Track and Orphan Drug designations but has not been approved by the FDA or another regulatory authority. Its safety and efficacy have not been established by regulatory authorities.
The submission followed the global, randomized, double-blind, placebo-controlled Phase 3 INSPIRE study. According to the companies, dersimelagon achieved statistically significant results across primary and secondary endpoints, including prolonging average daily sunlight exposure before the onset of prodromal symptoms. Detailed data were presented as a late-breaking presentation at the 2026 American Academy of Dermatology Annual Meeting.
“EPP and XLP are devastating lifelong diseases that can severely limit patients’ ability to live everyday lives free from sunlight-induced pain,” Akihisa Harada, CEO of Tanabe Pharma, said in the announcement.
Source
LEO Pharma press release. August 18, 2026.